1. [Technical Field of the Invention]
The present invention relates to an apparatus for driving switching elements, and more particularly to the apparatus for driving the voltage-controlled switching elements.
2. [Related Art]
It is known that this type of driving device is installed in a vehicle to drive switching elements configuring an inverter which is connected to an on-vehicle main device. For example, as disclosed in JP-A-2009-060358, this type of driving device has a function of shutting down an inverter when the current flowing through switching elements which are driven becomes equal to or more than a threshold current.
The reason why the current flowing through switching elements becomes equal to or more than a threshold current is that the voltage applied to its conduction control terminal is set to a high level. Specifically, in this case, the current in a non-saturated area exceeds the threshold current. This is a configuration for reducing loss of the switching elements.
The voltage applied to switching elements may be reduced when some sort of failure occurs in the driving device. In such a case, loss of the switching elements may become large and, further, drastic temperature rise may be caused accompanying generation of heat. However, depending on the function of shutdown, for example, such a failure may not be handled because the current passing through the switching elements is maintained at a level equal to or less than a threshold.